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feat: add solutions to lc problem: No.0809
No.0809.Expressive Words
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‎solution/0800-0899/0809.Expressive Words/README.md

Lines changed: 149 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -43,22 +43,170 @@ words = ["hello", "hi", "helo"]
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<!-- 这里可写通用的实现逻辑 -->
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**方法一：双指针**
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遍历 `words` 数组，对于每个单词 `t`，判断当前单词 `t` 是否可以通过扩张得到 `s`，如果可以，答案加一。
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问题的关键在于判断当前单词 `t` 是否可以通过扩张得到 `s`。
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我们可以使用双指针 `i` 和 `j` 分别指向 `s` 和 `t`，初始时 `i = j = 0`。
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如果 `i` 和 `j` 指向的字符不同，那么 `t` 无法通过扩张得到 `s`，直接返回 `false`；否则，我们需要判断 `s` 中 `i` 指向的字符的连续出现次数 `c1` 和 `t` 中 `j` 指向的字符的连续出现次数 `c2` 的关系。如果 `c1 < c2` 或者 `c1 < 3 && c1 != c2`，那么 `t` 无法通过扩张得到 `s`，直接返回 `false`；否则，将 `i` 和 `j` 分别右移 `c1` 和 `c2` 次。
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如果 `i` 和 `j` 都到达了字符串的末尾，那么 `t` 可以通过扩张得到 `s`，返回 `true`，否则返回 `false`。
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时间复杂度 $O(L)$，空间复杂度 $O(1)$。其中 $L$ 为 `words` 数组中所有单词的长度之和。
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<!-- tabs:start -->
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### **Python3**
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<!-- 这里可写当前语言的特殊实现逻辑 -->
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```python
53-
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class Solution:
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def expressiveWords(self, s: str, words: List[str]) -> int:
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def check(s, t):
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m, n = len(s), len(t)
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if n > m:
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return False
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i = j = 0
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while i < m and j < n:
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if s[i] != t[j]:
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return False
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k = i
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while k < m and s[k] == s[i]:
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k += 1
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c1 = k - i
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i, k = k, j
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while k < n and t[k] == t[j]:
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k += 1
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c2 = k - j
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j = k
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if c1 < c2 or (c1 < 3 and c1 != c2):
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return False
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return i == m and j == n
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return sum(check(s, t) for t in words)
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```
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### **Java**
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<!-- 这里可写当前语言的特殊实现逻辑 -->
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```java
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class Solution {
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public int expressiveWords(String s, String[] words) {
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int ans = 0;
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for (String t : words) {
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if (check(s, t)) {
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++ans;
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}
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}
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return ans;
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}
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private boolean check(String s, String t) {
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int m = s.length(), n = t.length();
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if (n > m) {
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return false;
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}
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int i = 0, j = 0;
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while (i < m && j < n) {
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if (s.charAt(i) != t.charAt(j)) {
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return false;
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}
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int k = i;
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while (k < m && s.charAt(k) == s.charAt(i)) {
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++k;
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}
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int c1 = k - i;
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i = k;
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k = j;
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while (k < n && t.charAt(k) == t.charAt(j)) {
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++k;
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}
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int c2 = k - j;
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j = k;
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if (c1 < c2 || (c1 < 3 && c1 != c2)) {
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return false;
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}
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}
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return i == m && j == n;
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}
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}
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```
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### **C++**
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```cpp
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class Solution {
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public:
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int expressiveWords(string s, vector<string>& words) {
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int ans = 0;
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for (string& t : words) ans += check(s, t);
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return ans;
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}
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int check(string& s, string& t) {
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int m = s.size(), n = t.size();
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if (n > m) return 0;
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int i = 0, j = 0;
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while (i < m && j < n) {
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if (s[i] != t[j]) return 0;
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int k = i;
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while (k < m && s[k] == s[i]) ++k;
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int c1 = k - i;
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i = k, k = j;
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while (k < n && t[k] == t[j]) ++k;
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int c2 = k - j;
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j = k;
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if (c1 < c2 || (c1 < 3 && c1 != c2)) return 0;
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}
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return i == m && j == n;
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}
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};
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```
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### **Go**
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```go
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func expressiveWords(s string, words []string) int {
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check := func(s, t string) bool {
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m, n := len(s), len(t)
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if n > m {
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return false
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}
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i, j := 0, 0
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for i < m && j < n {
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if s[i] != t[j] {
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return false
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}
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k := i
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for k < m && s[k] == s[i] {
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k++
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}
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c1 := k - i
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i, k = k, j
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for k < n && t[k] == t[j] {
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k++
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}
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c2 := k - j
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j = k
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if c1 < c2 || (c1 != c2 && c1 < 3) {
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return false
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}
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}
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return i == m && j == n
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}
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ans := 0
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for _, t := range words {
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if check(s, t) {
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ans++
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}
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}
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return ans
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}
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```
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### **...**

‎solution/0800-0899/0809.Expressive Words/README_EN.md

Lines changed: 135 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -55,13 +55,147 @@ We can&#39;t extend &quot;helo&quot; to get &quot;heeellooo&quot; because the gr
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### **Python3**
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```python
58-
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class Solution:
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def expressiveWords(self, s: str, words: List[str]) -> int:
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def check(s, t):
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m, n = len(s), len(t)
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if n > m:
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return False
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i = j = 0
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while i < m and j < n:
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if s[i] != t[j]:
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return False
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k = i
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while k < m and s[k] == s[i]:
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k += 1
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c1 = k - i
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i, k = k, j
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while k < n and t[k] == t[j]:
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k += 1
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c2 = k - j
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j = k
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if c1 < c2 or (c1 < 3 and c1 != c2):
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return False
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return i == m and j == n
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return sum(check(s, t) for t in words)
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```
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### **Java**
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```java
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class Solution {
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public int expressiveWords(String s, String[] words) {
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int ans = 0;
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for (String t : words) {
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if (check(s, t)) {
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++ans;
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}
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}
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return ans;
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}
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private boolean check(String s, String t) {
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int m = s.length(), n = t.length();
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if (n > m) {
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return false;
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}
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int i = 0, j = 0;
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while (i < m && j < n) {
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if (s.charAt(i) != t.charAt(j)) {
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return false;
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}
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int k = i;
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while (k < m && s.charAt(k) == s.charAt(i)) {
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++k;
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}
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int c1 = k - i;
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i = k;
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k = j;
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while (k < n && t.charAt(k) == t.charAt(j)) {
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++k;
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}
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int c2 = k - j;
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j = k;
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if (c1 < c2 || (c1 < 3 && c1 != c2)) {
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return false;
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}
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}
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return i == m && j == n;
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}
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}
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```
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### **C++**
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```cpp
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class Solution {
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public:
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int expressiveWords(string s, vector<string>& words) {
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int ans = 0;
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for (string& t : words) ans += check(s, t);
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return ans;
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}
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int check(string& s, string& t) {
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int m = s.size(), n = t.size();
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if (n > m) return 0;
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int i = 0, j = 0;
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while (i < m && j < n) {
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if (s[i] != t[j]) return 0;
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int k = i;
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while (k < m && s[k] == s[i]) ++k;
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int c1 = k - i;
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i = k, k = j;
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while (k < n && t[k] == t[j]) ++k;
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int c2 = k - j;
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j = k;
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if (c1 < c2 || (c1 < 3 && c1 != c2)) return 0;
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}
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return i == m && j == n;
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}
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};
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```
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### **Go**
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```go
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func expressiveWords(s string, words []string) int {
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check := func(s, t string) bool {
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m, n := len(s), len(t)
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if n > m {
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return false
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}
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i, j := 0, 0
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for i < m && j < n {
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if s[i] != t[j] {
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return false
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}
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k := i
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for k < m && s[k] == s[i] {
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k++
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}
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c1 := k - i
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i, k = k, j
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for k < n && t[k] == t[j] {
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k++
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}
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c2 := k - j
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j = k
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if c1 < c2 || (c1 != c2 && c1 < 3) {
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return false
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}
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}
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return i == m && j == n
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}
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ans := 0
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for _, t := range words {
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if check(s, t) {
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ans++
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}
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}
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return ans
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}
65199
```
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### **...**

‎solution/0800-0899/0809.Expressive Words/Solution.cpp

Lines changed: 26 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,26 @@
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class Solution {
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public:
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int expressiveWords(string s, vector<string>& words) {
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int ans = 0;
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for (string& t : words) ans += check(s, t);
6+
return ans;
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}
8+
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int check(string& s, string& t) {
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int m = s.size(), n = t.size();
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if (n > m) return 0;
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int i = 0, j = 0;
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while (i < m && j < n) {
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if (s[i] != t[j]) return 0;
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int k = i;
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while (k < m && s[k] == s[i]) ++k;
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int c1 = k - i;
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i = k, k = j;
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while (k < n && t[k] == t[j]) ++k;
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int c2 = k - j;
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j = k;
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if (c1 < c2 || (c1 < 3 && c1 != c2)) return 0;
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}
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return i == m && j == n;
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}
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};

‎solution/0800-0899/0809.Expressive Words/Solution.go

Lines changed: 36 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,36 @@
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func expressiveWords(s string, words []string) int {
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check := func(s, t string) bool {
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m, n := len(s), len(t)
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if n > m {
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return false
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}
7+
i, j := 0, 0
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for i < m && j < n {
9+
if s[i] != t[j] {
10+
return false
11+
}
12+
k := i
13+
for k < m && s[k] == s[i] {
14+
k++
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}
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c1 := k - i
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i, k = k, j
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for k < n && t[k] == t[j] {
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k++
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}
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c2 := k - j
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j = k
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if c1 < c2 || (c1 != c2 && c1 < 3) {
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return false
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}
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}
27+
return i == m && j == n
28+
}
29+
ans := 0
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for _, t := range words {
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if check(s, t) {
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ans++
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}
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}
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return ans
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}

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